Non-metallic Doping Of Titanium Dioxide And Its Application In Photoelectrochemical Fuel Cells

Fossil energy has been rapidly consumed in the past decades duo to the development of the world economic.Energy crisis and environment detoriate are becoming worse along with utilization of fossile fuels.Therefore,it is urgent to develop a clean,and renewable energy.Specifically,an efficient energy technology is highly desired to address the devolopment of renewable energy.Among these techonogies,photoelectrochemical fuel cell?PEFC?has attracted more and more attention in recent years.The pricinple of PEFC is based on the oxidization of organic,biomaterials,or other chemicals in poluuted water solution to produce electricity under the assistance of sunlight.However,catalysts play central role in the PEFC.TiO2 is a promising photocatalyst by virtue of its high-performance,low-cost.However,it is needed to futher improve the performance of TiO₂ towards PEFC application.In this thesis,we have prepared the nonmetal-doped titanium dioxide composite materials and invesitgated their catalytic properties towards ethanol and the PEFC was constructed by coupling suitable cathode.The performance of the as-constructed PEFC was systematically investigated.?1?By using hydrothermal method and mechanical mixing techniques,we prepared a nitrogen-doped titanium dioxide ball that coated with carbon nanotubes.Compared with commercialized catalyst of P25,the as-prepared N-doped TiO₂ shows a siginificantincrease of nearly 5-fold towards oxidation of ethanol.When coupling with a platinum-carbon catalysts as cathode,a photoelectrochemical ethanol fuel cell was constructed.With the assistance of sunlight,we successfully convert chemical energy of ethanol to electrical energy.Under a sunlight irradiation of 100 mW·cm^-2,the ethanol PEFC gives an open circuit voltage of 0.93 V,a power density of 36?W·cm^-2.?2?Combined with the use of sol-gel method and hydrothermal mechanical mixing technology,we prepared S-doped TiO2 nanoparticles.We found that the the catalytical performace of the as-prepared S-TiO2 clearly relies on the amount of doped S elements.The enhanced performance of the S-TiO2 was systematically described by understanding the TiO2 doping mechanism.Finally,the S-TiO₂ was used as the anode and platinum-carbon catalyst was used as cathode to build a photoelectrochemical ethanol fuel cell.Under the sunlight irradiation of100 mW·cm^-2,the PEFC shows an open circuit voltage of 0.98 V,a power density of 20?W·cm^-2.This work provides that photoelectrochemical ethanol fuel cell is a new energy technology by realizeing the conversion of solar and chemical energy to electricity.